Stable instability: the natural history of personality disorders

Personality disorders were thought to be persistent and enduring, and ‘pervasiveness’ has always been considered to be a core diagnostic feature of these disorders. This is now realized to be untrue. Some core features of normal personality may indeed be persistent, but it is rare for an abnormal personality to remain immutable. The reasons for this are clarified in this article, and it is concluded that it is only when the abnormal personality interacts negatively with the environment that disorder is shown, and as environments frequently change apparent adaptation appears to occur.